Since I switched to spectrwm I found that I had to explicitly tell X to use the keyboard layout I find most useful.

Let’s say you’re using the US Intl. keyboard layout (the only sane layout if you ask me) and you need to enter special symbols and characters, the altgr-intl layout – aka French/English layout on RH and its siblings distros – is the way to go then as “all of the non-US keys are all hidden behind a single key: the right Alt key.”.

So in order to instruct X to use this useful keyboard layout you could:
1. Add the corresponding section to Xorg’s keyboard settings by creating the appropriate file in /etc/X11/xorg.conf.d – not really recommended as it is somewhat awkward nowadays and the least you fiddle with your admin account the less you probably end up messing it;
2. Just add setxkbmap -rules evdev -model evdev -layout us -variant altgr-int to your ~/.xinitrc file (or any other init script parsed by your WM);